Inter-carrier Interference Removal Using Reliability Weighting

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Solution Overview

Problem

Existing inter-carrier interference removal devices face challenges in accurately estimating and removing inter-carrier interference components in multipath fading environments with frequency selective channels, leading to errors and increased interference.

Innovation Solution

An inter-carrier interference removal device that calculates a reliability value for each carrier signal based on its frequency response characteristic, weights the signals accordingly, and uses these weighted signals to estimate and remove inter-carrier interference components, improving accuracy in frequency selective environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional ICI removal methods are used in multipath fading environments, then ICI removal is attempted, but estimation errors occur and interference increases due to frequency selectiveness and carrier level variations

Engineering Contradiction:
ImproveICI component estimation accuracyVSAvoidchannel characteristic estimation reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by calculating reliability values individually for each carrier signal based on its specific frequency response characteristic. Instead of treating all carriers uniformly, the system assigns different weights to different carriers according to their individual reliability, thereby improving ICI component estimation accuracy for each carrier while accounting for frequency selectiveness and carrier level variations in multipath fading environments.

Inventive Principle:
Principle #3Local quality

2Device complexity

If equalization is performed without reliability weighting, then processing is simplified, but estimation errors increase in frequency selective channels

Engineering Contradiction:
Improveprocessing complexityVSAvoidcarrier data estimation precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by introducing reliability values as a new parameter that modifies the equalization process. The reliability values, which are calculated based on frequency response characteristics, are used to weight carrier signals during ICI component estimation. This parameter change enables the system to adapt to frequency selective channels and improve carrier data estimation precision without fundamentally altering the overall processing architecture.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If all carrier signals are treated equally in ICI removal, then calculation is simplified, but performance degrades in frequency selective environments with varying carrier levels

Engineering Contradiction:
ImproveICI removal processing efficiencyVSAvoidcarrier level reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies local quality by calculating reliability values individually for each carrier signal based on its specific frequency response characteristic. Instead of treating all carriers uniformly, the system assigns different weights to different carriers according to their individual reliability, thereby improving ICI component estimation accuracy for each carrier while accounting for frequency selectiveness and carrier level variations in multipath fading environments.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP1940062B1Inter-carrier interference removal device and reception device using the same
Publication Date: 2016.09.07 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP1940062B1 patent drawingFigure 1
  • EP1940062B1 patent drawingFigure 2
  • EP1940062B1 patent drawingFigure 3

AI summary

An inter-carrier interface removal device can improve estimation accuracy of inter-carrier interference caused by Doppler shift in a received multi-carrier signal moving at a high speed, and a reception characteristic of the multi-carrier signal after removing the inter-carrier interference. The inter-carrier interference removal device includes: a channel estimation unit (101) estimating a channel frequency characteristic according to a carrier signal; an equalization unit (102) equalizing the carrier signal with the channel frequency characteristic and outputs tentative carrier data; a reliability value calculation unit (103) calculating a reliability value according to the channel frequency characteristic; a weighting unit (104) weighting the tentative carrier data with the reliability value; and an ICI component estimation unit (106) estimating an ICI component according to the weighted tentative carrier data and the estimated channel frequency characteristic; and an ICI removal calculation unit (107) removing the ICI component from the carrier signal.